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Abstract:

To access a network, an MTC device sends a channel request message to the
network over a random access channel. The channel request message
includes a device type indication and a resource type indication. The
device type indication may for example, indicate to the network that the
requesting device is an MTC device or non-MTC device. Upon receipt of the
channel request, the receiving network node can determine on the basis of
the device type indication and resource type indication whether to grant
or deny the access attempt, and to determine what resources to grant. The
channel request message may further include a call duration indication in
the channel request message if CS resources are requested for a voice
call or a priority indication if CS resources are requested for a data
transmission.

Claims:

1. A method of random access implemented by a wireless terminal in a
wireless communication network having circuit-switched (CS) resources and
packet-switched (PS) resources, said method comprising: sending a channel
request message over a random access channel from said wireless terminal
to said network to request assignment of resources; and including in said
channel request message a device type indication and resource type
indication specifying respectively the device type of the requesting
wireless terminal and the type of requested resources.

2. The method of claim 1 further comprising including, in a channel
request message requesting assignment of CS resources for a voice call, a
call duration indication.

4. The method of claim 1 further comprising including, in a channel
request message requesting assignment of CS resources for a data
transmission, a priority indication.

5. The method of claim 4 wherein the priority indication comprises
predetermined bit patterns corresponding to a predetermined set of
priorities.

6. A method of random access implemented by a base station in a wireless
communication network, said method comprising: receiving a channel
request message over a random access channel from a wireless terminal
requesting assignment of resources; and determining a device type of the
requesting wireless terminal from a device type indication in said
channel request message; determining a type of a requested resource from
a resource type indication in said channel request message; granting
access to the requested resource based on said indicated device type and
resource type.

7. The method of claim 6 further comprising determining an expected call
duration from a call duration indication in a channel request message
requesting assignment of CS resources for a voice call.

9. The method of claim 6 further comprising determining a priority of a
data transmission from a priority indication in a channel request message
requesting CS resources for a data transmission.

10. The method of claim 9 wherein the priority indication comprises
predetermined bit patterns corresponding to a predetermined set of
priorities.

11. A wireless terminal comprising: a transceiver for communicating with
a base station in a wireless communication network; a processing circuit
configured to control operation of said transceiver, said processing
circuit including a random access controller configured to: send a
channel request message over a random access channel from said wireless
terminal to said network to request assignment of resources; and include
in said channel request message a device type indication and resource
type indication specifying respectively the device type of the requesting
wireless terminal and a type of requested resources.

12. The wireless terminal of claim 11 wherein said channel request
message requests assignment of CS resources for a voice call and wherein
the random access controller is further configured to include a call
duration indication in said channel request message.

14. The wireless terminal of claim 11 wherein said channel request
message requests assignment of CS resources for a data transmission, and
wherein said random access controller is further configured to include a
priority indication in said channel request message.

15. The wireless terminal of claim 14 wherein the priority indication
comprises predetermined bit patterns corresponding to a predetermined set
of priorities.

16. A base station in a wireless communication network, said base station
comprising: a transceiver circuit for communicating with wireless
terminals; a processing circuit configured to control operation of said
transceiver circuit, said processing circuit including a access
controller configured to: receive, from a wireless terminal over a random
access channel, a channel request message requesting assignment of
resources; determine a type of the requesting wireless terminal from a
device type indication in the channel request message; determine a type
of a requested resource from a resource type indication in said channel
request message; grant access to the requested resource based on said
indicated device type and resource type.

17. The base station of claim 16 wherein said access controller is
further configured to detect a call duration indication in a channel
request message requesting assignment of CS resources for a voice call.

18. The base station of claim 17 wherein the call duration indication
comprises predetermined bit patterns corresponding to a predetermined set
of permissible call durations.

19. The base station of claim 16 wherein said access controller is
further configured to detect a priority indication in a channel request
message requesting assignment of CS resources for a data transmission.

20. The base station of claim 19 wherein the priority indication
comprises predetermined bit patterns corresponding to a predetermined set
of priorities.

21. A method of random access in a wireless communication network, said
method comprising: sending a channel request message to the network over
a random access channel to request assignment of CS resources for a voice
call; and transmitting device type information and call duration
information to said base station in said channel request message.

23. The method of claim 22 wherein the call duration information
indicates one of a predetermined set of permissible call durations.

24. A method of controlling access to circuit-switched resources in a
wireless communication network, said method comprising: receiving, from a
wireless terminal over a random access channel, a channel request message
requesting assignment of CS resources for a voice call; obtaining device
type information and call duration information from said channel request
message; and granting access to the requested resource based on the
device type information and the call duration information.

26. The method of claim 24 wherein the call duration information
indicates one of a predetermined set of permissible call durations.

27. A wireless terminal comprising: a transceiver for communicating with
a base station in a wireless communication network; a processing circuit
configured to control operation of said transceiver, said processing
circuit including a random access controller configured to: send a
channel request message to the network over a random access channel to
request assignment of CS resources for a voice call; and transmit device
type information and call duration information to said base station in
said channel request message.

29. The wireless terminal of claim 27 wherein the call duration
information indicates one of a predetermined set of permissible call
durations.

30. A base station in a wireless communication network, said base station
comprising: a transceiver circuit for communicating with wireless
terminals; a processing circuit configured to control operation of said
transceiver circuit, said processing circuit including a access
controller configured to: receive, from a wireless terminal over a random
access channel, a channel request message requesting assignment of CS
resources for a voice call; obtain device type information and call
duration information from said channel request message; and grant access
to the requested resource based on the device type information and the
call duration information.

31. The base station of claim 30 wherein the device type information
indicates that the wireless terminal comprises a machine-type
communication (MTC) device.

32. The base station of claim 30 wherein the call duration information
indicates one of a predetermined set of permissible call durations.

33. A method of random access in a wireless communication network, said
method comprising: sending a channel request message to the network over
a random access channel to request assignment of CS resources for a data
transmission; and transmitting device type information and priority
information to said base station in said channel request message.

35. The method of claim 34 wherein the priority information indicates one
of a predetermined set of permissible priorities.

36. A method of controlling access to circuit-switched resources in a
wireless communication network, said method comprising: receiving, from a
wireless terminal over a random access channel, a channel request message
requesting assignment of CS resources for a data transmission; obtaining
device type information and priority information from said channel
request message; and granting access to the requested resource based on
the device type information and the priority information.

38. The method of claim 36 wherein the priority information indicates one
of a predetermined set of permissible priorities.

39. A wireless terminal comprising: a transceiver for communicating with
a base station in a wireless communication network; a processing
configured to control operation of said transceiver, said processing
circuit including a random access controller configured to: send a
channel request message to the network over a random access channel to
request assignment of CS resources for a data transmission; and transmit
device type information and priority information to said base station in
said channel request message.

41. The wireless terminal of claim 39 wherein the priority information
indicates one of a predetermined set of permissible priorities.

42. A base station in a wireless communication network, said base station
comprising: a transceiver circuit for communicating with wireless
terminals; a processing circuit configured to control operation of said
transceiver circuit, said processing circuit including an access
controller configured to: receive, from a wireless terminal over a random
access channel, a channel request message requesting assignment of CS
resources for a data transmission; obtain device type information and
priority information from said channel request message; and grant access
to the requested resource based on the device type information and the
priority information.

43. The base station of claim 42 wherein the device type information
indicates that the wireless terminal comprises a machine-type
communication (MTC) device.

44. The base station of claim 42 wherein the priority information
indicates one of a predetermined set of permissible priorities.

Description:

RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Patent
Application 61/358,147 filed Jun. 24, 2010, which is incorporated herein
by reference.

[0003] The random access channel (RACH) in mobile communication networks
provides contention-based access to wireless terminals to request
connection setup when no radio resources have been allocated to the
wireless terminal. In systems based on the GSM/EDGE standard, the
wireless terminal sends an access request message to the network on the
RACH to request allocation of resources. The access request message
includes a randomly generated bit sequence which, together with the rest
of the information provided within the access request, is referred to in
some protocols as the Request Reference information. The Request
Reference is used for identification purposes during contention
resolution and provides some degree of uniqueness for the accessing
wireless terminal in lieu of a larger identifier such as the IMSI (i.e.
the Request Reference minimizes the amount of information the wireless
terminal needs to send during the initial part of contention resolution
process). The wireless terminal then monitors the Access Grant Channel
(AGCH) for a response. The network may either accept or deny the access
request. If it accepts it, the network transmits an Immediate Assignment
(IA) message on the AGCH, identifying the wireless terminal by the
Request Reference value included in the access request message and
assigning it radio resources. If the network denies access to the
requesting wireless terminal, it transmits an Immediate Assignment Reject
(IAR) message identifying the wireless terminal by the Request Reference
value included in the access request message.

[0004] The anticipated introduction of a large volume of machine-type
communication (MTC) devices in the near future will greatly increase the
demand on the resources of the communication network. MTC devices are
devices, such as meters or sensors, that collect and send data to an MTC
server or other MTC device over a communication network. It is expected
that MTC devices will far outnumber non-MTC devices, such as user
terminals for voice and data communications by human users. It would be
beneficial to know the type of device and the type of requested resources
when an MTC device attempts to access the network. This information could
be factored into decision by the network to grant or deny access to the
network and to allocate resources to the requesting device.

SUMMARY

[0005] The present invention provides methods and apparatus for
controlling network access by MTC devices or other wireless terminals. To
access the network, the MTC device sends an access request message (also
known as a channel request message) to the network over a random access
channel. The channel request message includes a device type indication
and a resource type indication. The device type indication may, for
example, indicate to the network that the requesting device is an MTC
device or non-MTC device. The resource type indication may for example,
indicate that the request is for circuit-switched (CS) or packet-switched
(PS) resources. Upon receipt of the channel request message, the
receiving network node can determine on the basis of the device type
indication and resource type indication whether to accept or reject the
access attempt, and to determine what resources to grant.

[0006] In some embodiments of the invention, the channel request message
may include additional call related parameters. For example, in the case
of a voice call, the requesting device may include a call duration
indication in the channel request message. In the case of a data
transmission, the requesting device may include a priority indication in
the channel request message. The network can factor the additional
call-related parameters in its decision to accept or reject the system
access, and to determine what resources to grant.

[0007] Exemplary embodiments of the invention comprise random access
methods implemented by a wireless terminal. In one exemplary random
access method, the wireless terminal sends a channel request message over
a random access channel to the network to request assignment of
resources. The channel request message includes a device-type indication
specifying a type of the requesting wireless terminal (e.g., MTC or
non-MTC) and a resource type indication specifying the type of resources
requested (e.g., CS or PS). For the case where the resource type
indicates that CS resources are requested, the channel request message
includes an access type indication specifying the type of access
requested (e.g., a CS resource for voice call or a CS resource for a data
transmission).

[0008] In another exemplary random access method, the wireless terminal
sends a channel request message over a random access channel to the
network to request assignment of CS resources for a voice call. The
resource type (i.e. CS resources) and access type (i.e. voice call) may
be specified respectively by a resource type and access type indication
in the channel request message. The channel request message includes a
device-type indication specifying a type of the requesting wireless
terminal (e.g., MTC or non-MTC), and a call duration indication
specifying an expected duration of the call.

[0009] In another exemplary embodiment, the wireless terminal sends a
channel request message over a random access channel to the network to
request assignment of CS resources for a data transmission. The resource
type (i.e. CS resources) and access type (i.e. data transmission) may be
specified respectively by a resource type and access type indication in
the channel request message. The channel request message includes a
device-type indication specifying a type of the requesting wireless
terminal (e.g., MTC or non-MTC device), and a priority indication
specifying the priority of the data transmission.

[0010] Some embodiments of the invention comprise wireless terminals
configured to access a network over a random access channel. One
exemplary wireless terminal comprises a transceiver for communicating
with a base station in a wireless communication network, and a processing
circuit configured to control operation of said transceiver. The
processing circuit includes a radio resource controller configured to
send a channel request message over a random access channel to the
network to request assignment of resources. The channel request message
includes a device type indication specifying the device type of the
requesting wireless terminal (e.g., MTC or non-MTC) and a resource type
indication specifying the type of requested resources (e.g., CS or PS).

[0011] Another exemplary wireless terminal comprises a transceiver for
communicating with a base station in a wireless communication network,
and a processing circuit configured to control operation of said
transceiver. The processing circuit includes a radio resource controller
configured to send a channel request message over a random access channel
to the network to request assignment of CS resources for a voice call.
The resource type (i.e. CS resources) and access type (i.e. voice call)
may be specified respectively by a resource type and access type
indication in the channel request message. The channel request message
includes a device type indication specifying a type of the requesting
wireless terminal, and call duration indication specifying an expected
duration of the voice call.

[0012] Still another wireless terminal comprises a transceiver for
communicating with a base station in a wireless communication network,
and a processing circuit configured to control operation of said
transceiver. The processing circuit includes a radio resource controller
configured to send a channel request message over a random access channel
to the network to request assignment of CS resources for a data
transmission. The resource type (i.e. CS resources) and access type (i.e.
data transmission) may be specified respectively by a resource type and
access type indication in the channel request message. The channel
request message includes a device type indication specifying a type of
the requesting wireless terminal, and priority indication specifying a
priority of the data transmission.

[0013] Exemplary embodiments of the invention comprise access control
methods implemented by a base station or other network node in a mobile
communication network. In one exemplary embodiment, the base station or
network node receives a channel request message over a random access
channel from a wireless terminal. The base station determines a type of
the requesting wireless terminal from a device type indication in the
channel request message and the type of the requested resource from a
resource type indication in the channel request message. The base station
grants access to the requested resource based on said indicated device
type and resource type.

[0014] In another exemplary access control method, the base station or
network node receives, from a wireless terminal over a random access
channel, a channel request message requesting assignment of CS resources
for a voice call. The resource type (i.e. CS resources) and access type
(i.e. voice call) may be specified respectively by a resource type and
access type indication in the channel request message. The base station
determines a type of the requesting wireless terminal from a device type
indication in the channel request message, and the expected duration of
the voice call from a call duration indication in the channel request
message. The base station grants access to the requested resource based
on said indicated device type and call duration.

[0015] In another exemplary access control method, the base station or
network node receives, from a wireless terminal over a random access
channel, a channel request message requesting assignment of CS resources
for a data transmission. The resource type (i.e. CS resources) and access
type (i.e. data transmission) may be specified respectively by a resource
type and access type indication in the channel request message. The base
station determines a type of the requesting wireless terminal from a
device type indication in the channel request message, and the priority
of the data transmission from a priority indication in the channel
request message. The base station grants access to the requested resource
based on said indicated device type and priority.

[0016] Other exemplary embodiments comprise base stations for controlling
network access by wireless terminals. One exemplary base station
comprises a transceiver circuit for communicating with wireless
terminals, and a processing circuit configured to control operation of
said transceiver circuit. The processing circuit includes a radio
resource controller configured to receive, from a wireless terminal over
a random access channel, a channel request message requesting assignment
of resources; to determine a type of the requesting wireless terminal
from a device type indication in said channel request message; to
determine a type of the requested resource from a resource type
indication in the channel request message; and to grant access to the
requested resource based on said indicated device type and resource type.

[0017] Another exemplary embodiment of the base station comprises a
transceiver circuit for communicating with wireless terminals, and a
processing circuit configured to control operation of said transceiver
circuit. The processing circuit includes a radio resource controller
configured to receive, from a wireless terminal over a random access
channel, a channel request message requesting assignment of CS resources
for a voice call. The resource type (i.e. CS resources) and access type
(i.e. voice call) may be specified respectively by a resource type and
access type indication in the channel request message. The radio resource
controller is further configured to obtain device type information, and
call duration information from said channel request message; and to grant
access to the requested resource based on said indicated device type and
call duration.

[0018] Another exemplary embodiment of the base station comprises a
transceiver circuit for communicating with wireless terminals, and a
processing circuit configured to control operation of said transceiver
circuit. The processing circuit includes a radio resource controller
configured to receive, from a wireless terminal over a random access
channel, a channel request message requesting assignment of CS resources
for a data transmission. The resource type (i.e. CS resources) and access
type (i.e. data transmission) may be specified respectively by a resource
type and access type indication in the channel request message. The radio
resource controller is further configured to obtain device type
information, and call duration information from the channel request
message; and to grant access to the requested resource based on said
indicated device type and call duration.

[0028]FIG. 10 illustrates an exemplary base station to control network
access by MTC devices as herein described.

DETAILED DESCRIPTION

[0029] Referring now to the drawings, FIG. 1 illustrates an exemplary
wireless communication network 10 including a core network 12, a
plurality of base stations 20, and a plurality of wireless terminals 100.
The communication network 10 may, for example, comprise a mobile
communication network 12 that operates according to any communication
standard that employs a contention-based random access channel (RACH).
For illustrative purposes, an exemplary embodiment of the present
invention will be described in the context of a network operating
according to the GSM/EDGE (Global System for Mobile Communication (GSM)
Packet Radio Service) standard. Those skilled in the art will appreciate,
however, that the present invention is more generally applicable to other
wireless communication systems, including Wideband Code Division Multiple
Access (WCDMA), Long-Term Evolution (LTE), and Worldwide Interoperability
for Microwave Access (WiMAX) systems. The mobile communication network 12
includes a plurality of base stations 20 that provide network access to
mobile wireless terminals 100. The mobile communication network 12
connects to an external packet data network 14, such as the Internet. The
wireless terminals 100 may communicate with one or more servers 30
connected to the mobile communication network 12 or packet data network
14.

[0030] The wireless terminals 100 may comprise machine-type communication
(MTC) devices for collecting and reporting of data over a communication
network or non-MTC devices. Machine Type Communications (MTC) has been
defined as a specific type of wireless communication network traffic.
See, e.g., 3GPP Technical Report 23.888, "System Improvements for
Machine-Type Communications," the disclosure of which is incorporated
herein by reference in its entirety. One example of an MTC device is a
gas or power meter with a wireless transceiver for reporting at
predetermined time periods usage of gas or electrical power to the MTC
server 30. Non-MTC devices are devices, such as a cell phone, smart
phone, laptop computer, etc., used for voice and data communications by
human users. An MTC device may comprise a dedicated device specifically
for data collection and reporting. In other embodiments, a combined
wireless terminal 100 may function part of the time as a MTC device and
part of the time as a non-MTC device.

[0031] In order to send the data, a wireless terminal 100 must first
establish a connection with the communication network 10. Typically, the
wireless terminal 100 registers with the communication network 10 on
power up. After registering with the network 10, the wireless terminal
100 may enter an IDLE mode. In the IDLE mode, the wireless terminal 100
does not have an established connection with a base station 20. When the
wireless terminal 100 has data to send, it uses a random access procedure
to request assignment of resources. In one exemplary embodiment for a
GSM/EDGE network, the mobile wireless terminal initiates the random
access procedure by sending a channel request message to the network over
a random access channel. In response to the channel request message, the
base station 20 may decide to allow the access attempt or to deny the
access attempt. If the access attempt is allowed, the base station 20
assigns resources for the system access.

[0032] In exemplary embodiment of the present invention, the channel
request message sent by an MTC device includes a device type indication
specifying to the network the type of the requesting device. For example,
the device type indication may indicate to the network that it is either
an MTC device or non-MTC device. Other device types could also be
defined. The channel request message may also include service related
information, indicating, for example, type of resources being requested,
the expected call duration, a priority, and other service related
information. The network may factor the device type and service related
information received as part of the channel request into its decision
whether to grant or deny access and what resources to grant.

[0033]FIG. 2 illustrates an exemplary random access procedure 200
implemented by a wireless terminal 100 according to one embodiment. When
the wireless terminal 100 has data to send, the wireless terminal 100
sends a channel request message (CRM) over a random access channel (RACH)
to the base station 20 (block 202). The wireless terminal 100 includes in
the CRM a device-type indictor and resource-type indication (block 204).
The device-type indication indicates the type of the requesting wireless
terminal 100, and the resource-type indication indicates the type of
resources being requested. For example, the device-type indication may
indicate to the base station 20 that the wireless terminal 100 is either
an MTC device or non-MTC device. The resource-type indication may
indicate that assignment of either circuit-switched (CS) resources or
packet-switched (PS) resources is being requested by the wireless
terminal.

[0034] FIG. 3 illustrates a corresponding access control method 210
implemented by the base station 20. The base station 20 receives the
channel request message from the wireless terminal 100 over the random
access channel (block 212). Upon receipt of the channel request message,
the base station 20 determines the type of the requesting wireless
terminal 100 from the device-type indication (block 214) and the type of
resources requested from the resource-type indication (block 216). Based
on the indicated device type and resource type, the base station 20
either accepts or rejects the access attempt (block 218). If the access
attempt is accepted, the base station 20 grants resources to the wireless
terminal 100. The wireless terminal 100 may be notified of the grant
decision by sending a grant message (e.g., immediate assignment message)
to the wireless terminal 100.

[0035]FIG. 4 illustrates another exemplary random access procedure 220
implemented by a wireless terminal 100. In this embodiment, the wireless
terminal 100 sends a channel request message over a random access channel
to the base station 20 to request assignment of CS resources for a voice
call (block 222). The resource type (i.e. CS resources) and access type
(i.e. voice call) may be specified respectively by a resource type and
access type indication in the channel request message. The wireless
terminal 100 includes a device-type indication and call duration
indication in the channel request message (block 224). The device-type
indication may indicate, for example, that the wireless terminal 100 is
either an MTC or non-MTC device. Other device types could be defined. The
call duration indication specifies the expected maximum duration of the
call. As will be hereinafter described, the wireless terminal 100 may be
pre-configured with a subset of permissible call durations. The call
duration indication may comprise two or more bits indicating one of the
pre-configured call durations. For example, two bits can be used to
indicate call durations of 15 seconds, 30 seconds, 60 seconds, and
unlimited. Additional bits could be used to produce finer gradations in
call duration.

[0036] FIG. 5 illustrates a corresponding access control method 230
implemented by the base station 20. The base station 20 receives, from a
wireless terminal 100 over a random access channel, a channel request
message requesting CS resources for a voice call (block 232). The
resource type (i.e. CS resources) and access type (i.e. voice call) may
be specified respectively by a resource type and access type indication
in the channel request message. The base station 20 obtains device-type
information and call duration information from the channel request
message (blocks 234, 236). The device-type information may indicate, for
example, that the requesting wireless terminal 100 is either an MTC
device or non-MTC device. The call duration information specifies the
expected call duration from a predetermined set of permissible call
durations. Based on the device-type information and call duration
information in the channel request message, the base station 20
determines whether to accept or reject the access attempt and, if
accepted, what resources to grant (block 238).

[0037]FIG. 6 illustrates another exemplary random access procedure 240
implemented by a wireless terminal 100. In this embodiment, the wireless
terminal 100 sends a channel request message over a random access channel
to the base station 20 to request CS resources for a data transmission
(e.g., SMS message) (block 242). The resource type (i.e. CS resources)
and access type (i.e. data transmission) may be specified respectively by
a resource type and access type indication in the channel request
message. The wireless terminal 100 includes a device-type indication and
priority indication in the channel request message (block 244). The
device-type indication may indicate, for example, that the wireless
terminal 100 is either an MTC or non-MTC device. Other device types could
be defined. The priority indication specifies the priority of the data
transmission. As will be hereinafter described, the wireless terminal 100
may be pre-configured with a subset of permissible priorities. The
priority indication may comprise two or more bits indicating one of the
pre-configured call durations.

[0038] FIG. 7 illustrates a corresponding access control method 250
implemented by the base station 20. The base station 20 receives, from a
wireless terminal 100 over a random access channel, a channel request
message requesting CS resources for a data transmission (block 252). The
resource type (i.e. CS resources) and access type (i.e. data
transmission) may be specified respectively by a resource type and access
type indication in the channel request message. The base station 20
obtains device-type information and priority information from the channel
request message blocks 254, 256). The device-type information may
indicate, for example, that the requesting wireless terminal 100 is
either an MTC device or non-MTC device. The priority information
specifies a priority of the data transmission. Based on the device-type
information and priority information in the channel request message, the
base station 20 determines whether to accept or reject the access attempt
and, if accepted, what resources to grant (block 258).

[0039] The procedures shown in FIGS. 2-7 can be implemented in GSM/EDGE
networks using the EGPRS packet channel request message transmitted over
a packet random access channel (PRACH). The EGPRS packet channel request
message comprises eleven bits providing a Request Reference used for
identification purposes during contention resolution and provides some
degree of uniqueness for the requesting wireless terminal 100. Unused
code points within the EGPRS packet channel request message can be used
to indicate when an MTC device is attempting a system access, the type of
resources (e.g., CS or PS) being requested, and the access type (e.g.
voice call or data transmission). Depending on the access type, bits in
the EGPRS packet channel request message can be used to indicate call
duration (for voice calls) or priority (for data transmission).

[0040] FIG. 8 illustrates an exemplary EGPRS packet channel request
message 50 for implementing the procedures shown in FIGS. 2-5. As shown
in FIG. 6, the EGPRS packet channel request message comprises a
device-type indication (3 bits) 52, a resource-type indication (1 bit)
54, an access-type indication (1 bit) 56, a call duration indication or
priority indication depending on the access type (2 bits) 58, and four
random bits (4 bits) 60. In this embodiment, a device-type indication
with a value of "111" indicates that the requesting device is an MTC
device. The resource-type indication is set to "0" for packet-switched
resources and to "1" for circuit-switched resources. The message
structure is fully compliant with the existing GSM/EDGE standard.

[0041] By including a device type and resource type indication in the
channel request message, a base station 20 is able to determine when an
MTC device is attempting to access the network and the type of resource
requested, which may factor into the base station's decision to accept or
reject any given access attempt. Additionally, when an MTC device
requests assignment of CS resources, it may indicate whether the CS
resources will be used for a voice call or data transmission (e.g., SMS
message) by including an access type indication. In the case of a voice
call, the MTC device can indicate the expected duration of the voice
call. In the case of a data transmission, the MTC device may indicate the
priority of the data transmission. Allowing the wireless terminal 100 to
indicate the type of activity (voice or data transmission), as well as
call-related parameters (e.g., call duration or priority) enables the
base station 20 to take these factors into account when making radio
resource management decisions.

[0042] When an MTC device is activated, it can be configured to support a
predetermined set of possible call durations for voice calls, and a
predetermined set of priorities for data transmissions. For example, as
noted above, the MTC device may be configured to support calls having
maximum duration of 15, 30, 60, and unlimited minutes. Any one of four
different priorities for data transmissions may be indicated.

[0043] A number of different methods may be used to configure the MTC
device with permissible call durations and priorities. These methods
include: [0044] 1) pre-configuring the SIM card of an MTC device with a
set of permissible call durations and a set of priorities; [0045] 2)
over-the-air (OTA) programming to configure the MTC device with a set of
permissible call durations and a set of priorities; [0046] 3) 3GPP
non-access stratum (NAS) signaling to configure the MTC device with a set
of permissible call durations and a set of priorities. For example, NAS
signaling could be used to configure the MTC device during a GPRS attach
procedure. Alternatively, NAS signaling between the MTC device and an MTC
server can be used to configure the MTC device.

[0047]FIG. 9 illustrates an exemplary wireless terminal 100 that may
function as an MTC device, non-MTC device, or both. The wireless terminal
100 includes a processing circuit 110 connected to a transceiver circuit
150 that communicates with base stations 20 in the mobile communication
network 10. The processing circuit 110 includes a random access
controller 120 and memory 130 for storing program code 140 controlling
operation of the wireless terminal 100. The program code 140 includes
code for performing the random access procedures as herein described. The
transceiver circuit 150 comprises a receiver 160 and transmitter 170 for
communicating with the base station 20. The transceiver circuit 150 may
operate, for example, according to the GSM/EDGE standard or other
communication standard.

[0048]FIG. 10 illustrates an exemplary base station 20 that implements
the access control functions as herein described. The base station 20
includes a processing circuit 30 connected to a wireless transceiver
circuit 50 that communicates with wireless terminals 100 in the mobile
communication network 10, and a network interface 95. The processing
circuit 30 includes an access controller 40 and memory 50 for storing
program code 60 controlling operation of the base station 20. The program
code 60 includes code for performing the access control procedures as
herein described. The transceiver circuit 70 comprises a receiver 80 and
transmitter 90 for communicating with the base station 20. The
transceiver circuit 70 may operate, for example, according to the
GSM/EDGE standard or other communication standard. The network interface
95 enables the base station 20 to communicate with other base stations 20
and network nodes within the core network 12.

[0049] The present invention may, of course, be carried out in other
specific ways than those herein set forth without departing from the
scope and essential characteristics of the invention. The present
embodiments are, therefore, to be considered in all respects as
illustrative and not restrictive, and all changes coming within the
meaning and equivalency range of the appended claims are intended to be
embraced therein.